What Exactly Is UAV Photogrammetry?

Photogrammetry is the science of making measurements from photographs. Traditionally, images from an airplane, camera rig or handheld camera were used for photogrammetry. Now drones are offering a more accurate, efficient and cost effective way to collect images for processing.

To ensure high quality and highly accurate results, multiple overlapping photos (65 to 90%) of the ground or structure are taken as the UAV flies along an autonomous programmed flight path. To overlap photos of an object or land by up to 90% would be impossible to complete accurately by pilot navigation, but a UAV which has waypoint navigation technology can complete this process in minutes.

Autonomous flight path plan using waypoint navigation.

3D Maps And Models

To create 3D maps from aerial photogrammetry, the camera is usually pointed vertically towards the ground (although flights can be planned to include oblique imagery). Following pre-flight checks, the flight is conducted autonomously and the images stored on the SD card aboard the UAV.

Mapping Software showing locations of the 300+ images taken of 14 acre site

Once the data is downloaded the photogrammetry software uses the images to generate point clouds, digital surface models, orthomosaics, textured models and more. Software like Pix4Dmapper can now process thousands of overlapping images of a site and produce centimeter-accurate, full-color 3D models and 2D orthophotos in a matter of hours. These point clouds, maps and 3D models can then be used to accurately measure distances, areas and volumes, 3D visualisation, fly-through videos or they can be exported to many other platforms such as autoCAD, GIS or BIM software programs 

Point Cloud Volume Calculation

Industry Use and Advantages

Industry applications for UAV Mapping & Survey are almost endless and include Mapping, Transport Planning, Surveying, Construction, Mining, Urban Planning, Agriculture, Forestry and Land Management, Environmental Agencies etc.

They can be utilised on a project from initial survey, planning and site monitoring / project tracking, through stakeholder updating and marketing to maintenance and inspection.

The advantages that UAV have over traditional methods relate mainly to the speed, accuracy, quality of data and ease of repeatability that the system provides for measuring, monitoring and documenting projects. Savings in cost and time are seen when compared to traditional methods. Aerial imagery may provide early warning of unforeseen issues and enables crucial decisons to be discussed and made using the latest imagery available, Hazardous areas can also be surveyed without risk to personnel and most mapping can be conducted without having to enter that site, in the case of construction projects.

3D Mesh Model